The present invention generally relates to electric cable connectors, and, more particularly, is concerned with an electrical connector insert having an improved seal from the environment and that will mate a standard receptacle to a cable having a different number and configuration of conductors than those of the standard receptacle.
In the offshore seismic exploration industry, streamers carrying hydrophone and geophone sensors are towed behind exploration vessels for receiving reflected acoustic signals produced by seismic wave generating sources. The streamers are connected to the vessels by lead-in cables which carry electrical power to the streamers, and seismic data and telemetry from the streamers, to data processing equipment aboard the towing vessel. In ocean bottom seismic exploration, the seismic signals are received by hydrophone and/or geophone sensors connected to cables laid directly on the ocean floor. These ocean bottom cables are also connected to the vessel by lead-in cables.
All of the various streamers and cables are electrically and mechanically connected end-to-end by cable connectors having inserts designed to seal the interconnection from the environment, particularly from ingress by sea water, which results in the loss of electrical integrity. When leakage of water into a connector interface causes an electrical short, the seismic signal shooting and data collection must be stopped and the lengthy cables leading to the shorted connector pulled aboard the vessel so that the failed connector can be repaired or replaced. The exploration shooting down time required to replace a shorted cable connector is significant and very expensive.
In the offshore seismic exploration industry, a widely used, standard cable connector or receptacle insert is the Syntrak 37-pin insert. This Syntrak insert has 37 pins or mating sockets arranged in a fixed configuration and spacing that was chosen years ago when this connector was first designed. This standard insert includes a cylindrical metal shell with the conductive pins or sockets attached at one end of the shell and fixed in place by a molded elastomer. However, no sealing devices are included at the opposite end of this connector.
The Syntrak 37-pin insert is installed on a wide range of seismic cables and streamers used in the industry. The various types of cables and streamers which must be connected to this industry standard insert have varying numbers and arrangements or configurations of electrical power, data, or telemetry conductors. The number or configuration of the conductors in these cables usually do not match the standard insert. For example, ten of the pins or sockets on the 37-pin insert are preallocated to power. Depending on the wire gauge of its power conductors, a connecting cable may have two, four, ten, or twelve insulated power conductors that must be connected to these ten pins or sockets on the Syntrak insert. If, for example, the connecting cable has two power conductors, each of these conductors must be transitioned into five separate, smaller diameter conductors for connection to a respective five of the ten pins or sockets allocated to power on the Syntrak insert. This transition has heretofore been accomplished by splicing the smaller diameter wires to the larger diameter conductor. It is very difficult to seal a spliced transition between conductors from water leakage, especially where the spliced connection is exposed to flexing and contact with sea water. In addition, the contact interface within the body of the insert must be sealed from the environment. A spliced cable transition to a standard insert therefore presents two potential sources of water leakage and resulting failure: in the conductor splicing, and in the contact interface.
Various methods have been used in an attempt to seal presently used connector inserts. Sealing is commonly achieved at the rear of inserts by means of heat shrink, potting techniques, elastomeric boots, or combinations of these techniques. Each of these methods has problems. For example, heat shrinks and boots often leak if a conductor is flexed. Potting techniques are highly dependent on process control and the ability of the resins to adhere for:extended periods of time to various conductor insulation materials and grades. Since cables typically contain various insulation materials, the latter problem is not insignificant. Cables containing polyethylene insulation present particular sealing problems due to difficulties in adhering sealant to the polyethylene.
Consequently, a need exists for an improved electric cable insert that will mate with industry standard inserts, provide a reliable, high integrity seal from the environment, and accommodate most cable insulation materials. Preferably, such a cable insert will be capable of easy and quick assembly to a cable without soldering. Ideally, such an insert can be assembled and disassembled in the field.
The present invention provides an electric cable insert designed to satisfy the aforementioned needs. According to one aspect of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle having a plurality of sockets. The insert comprises a plurality of electrically conductive pins for connecting to respective sockets in the mating receptacle. The insert further includes a sealing gland having a plurality of bores therethrough, each of the cable conductors passing through a respective one of the bores in the sealing gland. Also included in the insert is means for electrically connecting the cable conductors to respective pins, and means for compressing the sealing gland so as to seal the insert from the environment.
According to an alternative embodiment of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle having a plurality of projecting pins. The insert comprises a plurality of receiving sockets for receiving respective pins on the mating receptacle. The insert further includes a sealing gland having a plurality of bores therethrough, each of the cable conductors passing through a respective one of the bores in the sealing gland. Also included in this embodiment of the insert is means for electrically connecting the cable conductors to the respective receiving sockets, and means for compressing the sealing gland so as to seal the insert from the environment.
According to another alternative embodiment of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle having a plurality of sockets, the number and configuration of the cable conductors being different from those of the sockets of the mating receptacle. The insert of this embodiment comprises a plurality of spaced receptacle pins for connecting to respective sockets in the mating receptacle, the number and configuration of the receptacle pins matching those of the receptacle. The insert also includes a sealing gland having a plurality of bores therethrough, the number and configuration of the bores matching those of the cable conductors. Each of the cable conductors passes through a respective one of the bores in the sealing gland. Also included in this embodiment of the insert is means, for conductively transitioning from the number and configuration of the cable conductors to the number and configuration of the sockets of the mating receptacle, and means for compressing the sealing gland so as to seal the insert from the environment.
According to still another alternative embodiment of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle. The insert comprises a housing having two opposite ends and an internal cavity. The first end of the housing is open to the cavity and the second end has a plurality of orifices therethrough. A seal is disposed within the housing. The seal has two opposite sides and a plurality of tubes projecting from one side thereof, the tube bores extending through to the opposite side of the seal. Each of the tubes mates with a respective orifice in the second end of the housing. A contact header is disposed within the housing adjacent the seal. The header has first and second sides. A plurality of electrically conductive pins extend through the header. Each pin has a first end projecting from the first side of the header and through a respective one of the seal tube bores for electrically connecting to the mating receptacle, and a second end projecting from the second side of the header. A seating gland is disposed within the housing adjacent the contact header. The gland has a plurality of bores therethrough. A driver compressively engages the gland so as to seal the insert from the environment. The driver has a plurality of bores therethrough. Each of the conductors of the cable passes through a respective one of the bores in the driver and in the sealing gland and electrically connects to the second end of one of the pins.
According to another alternative embodiment of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle having a plurality of projecting pins. The insert comprises a housing having two opposite ends and an internal cavity. The first end of the housing is open to the cavity and the second end has a plurality of orifices therethrough. A contact header is disposed within the housing adjacent the second end thereof. The header has first and second sides. The insert includes a plurality of spaced receiving sockets for receiving respective pins on the mating receptacle. Each receiving socket projects from the first side of the contact header. The receiving sockets pass through the contact header and have pins projecting from the second side of the contact header for connection to respective cable conductors. A sealing gland is disposed within the housing adjacent the contact header. The gland has a plurality of bores therethrough. A driver compressively engages the gland so as to seal the insert from the environment. The driver also has a plurality of bores therethrough. Each of the cable conductors passes through a respective one of the bores in the driver and in the sealing gland and electrically connects to one of the receiving socket pins.
According to still further alternative embodiment of the invention, an electric cable insert is provided for removably electrically connecting a cable having multiple conductors to a mating receptacle having a plurality of sockets. The number and configuration of the cable conductors is different from those of the sockets of the mating receptacle. The insert comprises a housing having two opposite ends and an internal cavity. The first end of the housing is open to the cavity, and the second end has a plurality of orifices therethrough. A seal is disposed within the housing. The seal has two opposite sides and a plurality of tubes project from one side thereof. The tube bores extend through to the opposite side of the seal. Each of the tubes mate with a respective orifice in the second end of the housing. A circuit card is provided for conductively transitioning from the number and configuration of the cable conductors to the number and configuration of the sockets of the mating receptacle. The circuit card has a first side and a second side. A plurality of spaced receptacle pins are attached to and extend from the first side of the circuit card and through respective orifices in the second end of the housing for connecting to respective sockets in the mating receptacle. The number and configuration of the receptacle pins match those of the receptacle sockets. A plurality of spaced contact pins are attached to and extend from the second side of the circuit card. The number and configuration of the contact pins match those of the cable conductors. A sealing gland is disposed within the housing adjacent the circuit card. The sealing gland has a plurality of bores therethrough. The number and configuration of the bores match those of the cable conductors. A driver compressively engages the gland so as to seal the insert from the environment. The driver has a plurality of bores therethrough. Each of the conductors of the cable passes through a respective one of the bores in the driver and in the sealing gland and connects to one of the contact pins extending from the circuit card.